St. Croix White and Barbados Blackbelly hair sheep ewes were managed using accelerated lambing in an extensive management system. Ewes grazed guinea grass (Panicum maximum) in a rotational grazing system throughout the year. Single sire breeding took place during 35-d periods in February, June or October with each flock producing three lamb crops every 2 years. Lambs were weaned at 63 d of age. Overall ewe fertility was 89.8% and prolificacy was 1.77 lambs per ewe lambing. Ewes that were bred in October had higher prolificacy (P < 0.0001) than ewes that were bred in February or June (1.87 vs 1.64 vs 1.73 lambs per ewe lambing, respectively). Ewes bred during October produced more triplets and fewer singles (P < 0.0001) than ewes bred at other times of the year. Ewe productivity, expressed as the ratio of litter weaning weight to ewe body weight, increased (P < 0.0001) from 41.6 to 50.3%) during a 10-yr period. These results show that hair sheep productivity can be sustained and enhanced using accelerated lambing and extensive management in the tropics.